1 files changed, 401 insertions, 0 deletions
diff --git a/third_party/git/t/t1512-rev-parse-disambiguation.sh b/third_party/git/t/t1512-rev-parse-disambiguation.sh
new file mode 100755
index 000000000000..18fa6cf40d37
--- /dev/null
+++ b/third_party/git/t/t1512-rev-parse-disambiguation.sh
@@ -0,0 +1,401 @@
+#!/bin/sh
+
+test_description='object name disambiguation
+
+Create blobs, trees, commits and a tag that all share the same
+prefix, and make sure "git rev-parse" can take advantage of
+type information to disambiguate short object names that are
+not necessarily unique.
+
+The final history used in the test has five commits, with the bottom
+one tagged as v1.0.0.  They all have one regular file each.
+
+  +-------------------------------------------+
+  |                                           |
+  |           .-------b3wettvi---- ad2uee     |
+  |          /                   /            |
+  |  a2onsxbvj---czy8f73t--ioiley5o           |
+  |                                           |
+  +-------------------------------------------+
+
+'
+
+. ./test-lib.sh
+
+if ! test_have_prereq SHA1
+then
+	skip_all='not using SHA-1 for objects'
+	test_done
+fi
+
+test_expect_success 'blob and tree' '
+	test_tick &&
+	(
+		for i in 0 1 2 3 4 5 6 7 8 9
+		do
+			echo $i
+		done &&
+		echo &&
+		echo b1rwzyc3
+	) >a0blgqsjc &&
+
+	# create one blob 0000000000b36
+	git add a0blgqsjc &&
+
+	# create one tree 0000000000cdc
+	git write-tree
+'
+
+test_expect_success 'warn ambiguity when no candidate matches type hint' '
+	test_must_fail git rev-parse --verify 000000000^{commit} 2>actual &&
+	test_i18ngrep "short SHA1 000000000 is ambiguous" actual
+'
+
+test_expect_success 'disambiguate tree-ish' '
+	# feed tree-ish in an unambiguous way
+	git rev-parse --verify 0000000000cdc:a0blgqsjc &&
+
+	# ambiguous at the object name level, but there is only one
+	# such tree-ish (the other is a blob)
+	git rev-parse --verify 000000000:a0blgqsjc
+'
+
+test_expect_success 'disambiguate blob' '
+	sed -e "s/|$//" >patch <<-EOF &&
+	diff --git a/frotz b/frotz
+	index 000000000..ffffff 100644
+	--- a/frotz
+	+++ b/frotz
+	@@ -10,3 +10,4 @@
+	 9
+	 |
+	 b1rwzyc3
+	+irwry
+	EOF
+	(
+		GIT_INDEX_FILE=frotz &&
+		export GIT_INDEX_FILE &&
+		git apply --build-fake-ancestor frotz patch &&
+		git cat-file blob :frotz >actual
+	) &&
+	test_cmp a0blgqsjc actual
+'
+
+test_expect_success 'disambiguate tree' '
+	commit=$(echo "d7xm" | git commit-tree 000000000) &&
+	# this commit is fffff2e and not ambiguous with the 00000* objects
+	test $(git rev-parse $commit^{tree}) = $(git rev-parse 0000000000cdc)
+'
+
+test_expect_success 'first commit' '
+	# create one commit 0000000000e4f
+	git commit -m a2onsxbvj
+'
+
+test_expect_success 'disambiguate commit-ish' '
+	# feed commit-ish in an unambiguous way
+	git rev-parse --verify 0000000000e4f^{commit} &&
+
+	# ambiguous at the object name level, but there is only one
+	# such commit (the others are tree and blob)
+	git rev-parse --verify 000000000^{commit} &&
+
+	# likewise
+	git rev-parse --verify 000000000^0
+'
+
+test_expect_success 'disambiguate commit' '
+	commit=$(echo "hoaxj" | git commit-tree 0000000000cdc -p 000000000) &&
+	# this commit is ffffffd8 and not ambiguous with the 00000* objects
+	test $(git rev-parse $commit^) = $(git rev-parse 0000000000e4f)
+'
+
+test_expect_success 'log name1..name2 takes only commit-ishes on both ends' '
+	# These are underspecified from the prefix-length point of view
+	# to disambiguate the commit with other objects, but there is only
+	# one commit that has 00000* prefix at this point.
+	git log 000000000..000000000 &&
+	git log ..000000000 &&
+	git log 000000000.. &&
+	git log 000000000...000000000 &&
+	git log ...000000000 &&
+	git log 000000000...
+'
+
+test_expect_success 'rev-parse name1..name2 takes only commit-ishes on both ends' '
+	# Likewise.
+	git rev-parse 000000000..000000000 &&
+	git rev-parse ..000000000 &&
+	git rev-parse 000000000..
+'
+
+test_expect_success 'git log takes only commit-ish' '
+	# Likewise.
+	git log 000000000
+'
+
+test_expect_success 'git reset takes only commit-ish' '
+	# Likewise.
+	git reset 000000000
+'
+
+test_expect_success 'first tag' '
+	# create one tag 0000000000f8f
+	git tag -a -m j7cp83um v1.0.0
+'
+
+test_expect_failure 'two semi-ambiguous commit-ish' '
+	# At this point, we have a tag 0000000000f8f that points
+	# at a commit 0000000000e4f, and a tree and a blob that
+	# share 0000000000 prefix with these tag and commit.
+	#
+	# Once the parser becomes ultra-smart, it could notice that
+	# 0000000000 before ^{commit} name many different objects, but
+	# that only two (HEAD and v1.0.0 tag) can be peeled to commit,
+	# and that peeling them down to commit yield the same commit
+	# without ambiguity.
+	git rev-parse --verify 0000000000^{commit} &&
+
+	# likewise
+	git log 0000000000..0000000000 &&
+	git log ..0000000000 &&
+	git log 0000000000.. &&
+	git log 0000000000...0000000000 &&
+	git log ...0000000000 &&
+	git log 0000000000...
+'
+
+test_expect_failure 'three semi-ambiguous tree-ish' '
+	# Likewise for tree-ish.  HEAD, v1.0.0 and HEAD^{tree} share
+	# the prefix but peeling them to tree yields the same thing
+	git rev-parse --verify 0000000000^{tree}
+'
+
+test_expect_success 'parse describe name' '
+	# feed an unambiguous describe name
+	git rev-parse --verify v1.0.0-0-g0000000000e4f &&
+
+	# ambiguous at the object name level, but there is only one
+	# such commit (others are blob, tree and tag)
+	git rev-parse --verify v1.0.0-0-g000000000
+'
+
+test_expect_success 'more history' '
+	# commit 0000000000043
+	git mv a0blgqsjc d12cr3h8t &&
+	echo h62xsjeu >>d12cr3h8t &&
+	git add d12cr3h8t &&
+
+	test_tick &&
+	git commit -m czy8f73t &&
+
+	# commit 00000000008ec
+	git mv d12cr3h8t j000jmpzn &&
+	echo j08bekfvt >>j000jmpzn &&
+	git add j000jmpzn &&
+
+	test_tick &&
+	git commit -m ioiley5o &&
+
+	# commit 0000000005b0
+	git checkout v1.0.0^0 &&
+	git mv a0blgqsjc f5518nwu &&
+
+	for i in h62xsjeu j08bekfvt kg7xflhm
+	do
+		echo $i
+	done >>f5518nwu &&
+	git add f5518nwu &&
+
+	test_tick &&
+	git commit -m b3wettvi &&
+	side=$(git rev-parse HEAD) &&
+
+	# commit 000000000066
+	git checkout master &&
+
+	# If you use recursive, merge will fail and you will need to
+	# clean up a0blgqsjc as well.  If you use resolve, merge will
+	# succeed.
+	test_might_fail git merge --no-commit -s recursive $side &&
+	git rm -f f5518nwu j000jmpzn &&
+
+	test_might_fail git rm -f a0blgqsjc &&
+	(
+		git cat-file blob $side:f5518nwu &&
+		echo j3l0i9s6
+	) >ab2gs879 &&
+	git add ab2gs879 &&
+
+	test_tick &&
+	git commit -m ad2uee
+
+'
+
+test_expect_failure 'parse describe name taking advantage of generation' '
+	# ambiguous at the object name level, but there is only one
+	# such commit at generation 0
+	git rev-parse --verify v1.0.0-0-g000000000 &&
+
+	# likewise for generation 2 and 4
+	git rev-parse --verify v1.0.0-2-g000000000 &&
+	git rev-parse --verify v1.0.0-4-g000000000
+'
+
+# Note: because rev-parse does not even try to disambiguate based on
+# the generation number, this test currently succeeds for a wrong
+# reason.  When it learns to use the generation number, the previous
+# test should succeed, and also this test should fail because the
+# describe name used in the test with generation number can name two
+# commits.  Make sure that such a future enhancement does not randomly
+# pick one.
+test_expect_success 'parse describe name not ignoring ambiguity' '
+	# ambiguous at the object name level, and there are two such
+	# commits at generation 1
+	test_must_fail git rev-parse --verify v1.0.0-1-g000000000
+'
+
+test_expect_success 'ambiguous commit-ish' '
+	# Now there are many commits that begin with the
+	# common prefix, none of these should pick one at
+	# random.  They all should result in ambiguity errors.
+	test_must_fail git rev-parse --verify 00000000^{commit} &&
+
+	# likewise
+	test_must_fail git log 000000000..000000000 &&
+	test_must_fail git log ..000000000 &&
+	test_must_fail git log 000000000.. &&
+	test_must_fail git log 000000000...000000000 &&
+	test_must_fail git log ...000000000 &&
+	test_must_fail git log 000000000...
+'
+
+# There are three objects with this prefix: a blob, a tree, and a tag. We know
+# the blob will not pass as a treeish, but the tree and tag should (and thus
+# cause an error).
+test_expect_success 'ambiguous tags peel to treeish' '
+	test_must_fail git rev-parse 0000000000f^{tree}
+'
+
+test_expect_success 'rev-parse --disambiguate' '
+	# The test creates 16 objects that share the prefix and two
+	# commits created by commit-tree in earlier tests share a
+	# different prefix.
+	git rev-parse --disambiguate=000000000 >actual &&
+	test_line_count = 16 actual &&
+	test "$(sed -e "s/^\(.........\).*/\1/" actual | sort -u)" = 000000000
+'
+
+test_expect_success 'rev-parse --disambiguate drops duplicates' '
+	git rev-parse --disambiguate=000000000 >expect &&
+	git pack-objects .git/objects/pack/pack <expect &&
+	git rev-parse --disambiguate=000000000 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ambiguous 40-hex ref' '
+	TREE=$(git mktree </dev/null) &&
+	REF=$(git rev-parse HEAD) &&
+	VAL=$(git commit-tree $TREE </dev/null) &&
+	git update-ref refs/heads/$REF $VAL &&
+	test $(git rev-parse $REF 2>err) = $REF &&
+	grep "refname.*${REF}.*ambiguous" err
+'
+
+test_expect_success 'ambiguous short sha1 ref' '
+	TREE=$(git mktree </dev/null) &&
+	REF=$(git rev-parse --short HEAD) &&
+	VAL=$(git commit-tree $TREE </dev/null) &&
+	git update-ref refs/heads/$REF $VAL &&
+	test $(git rev-parse $REF 2>err) = $VAL &&
+	grep "refname.*${REF}.*ambiguous" err
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguity errors are not repeated (raw)' '
+	test_must_fail git rev-parse 00000 2>stderr &&
+	grep "is ambiguous" stderr >errors &&
+	test_line_count = 1 errors
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguity errors are not repeated (treeish)' '
+	test_must_fail git rev-parse 00000:foo 2>stderr &&
+	grep "is ambiguous" stderr >errors &&
+	test_line_count = 1 errors
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguity errors are not repeated (peel)' '
+	test_must_fail git rev-parse 00000^{commit} 2>stderr &&
+	grep "is ambiguous" stderr >errors &&
+	test_line_count = 1 errors
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguity hints' '
+	test_must_fail git rev-parse 000000000 2>stderr &&
+	grep ^hint: stderr >hints &&
+	# 16 candidates, plus one intro line
+	test_line_count = 17 hints
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguity hints respect type' '
+	test_must_fail git rev-parse 000000000^{commit} 2>stderr &&
+	grep ^hint: stderr >hints &&
+	# 5 commits, 1 tag (which is a committish), plus intro line
+	test_line_count = 7 hints
+'
+
+test_expect_success C_LOCALE_OUTPUT 'failed type-selector still shows hint' '
+	# these two blobs share the same prefix "ee3d", but neither
+	# will pass for a commit
+	echo 851 | git hash-object --stdin -w &&
+	echo 872 | git hash-object --stdin -w &&
+	test_must_fail git rev-parse ee3d^{commit} 2>stderr &&
+	grep ^hint: stderr >hints &&
+	test_line_count = 3 hints
+'
+
+test_expect_success 'core.disambiguate config can prefer types' '
+	# ambiguous between tree and tag
+	sha1=0000000000f &&
+	test_must_fail git rev-parse $sha1 &&
+	git rev-parse $sha1^{commit} &&
+	git -c core.disambiguate=committish rev-parse $sha1
+'
+
+test_expect_success 'core.disambiguate does not override context' '
+	# treeish ambiguous between tag and tree
+	test_must_fail \
+		git -c core.disambiguate=committish rev-parse $sha1^{tree}
+'
+
+test_expect_success C_LOCALE_OUTPUT 'ambiguous commits are printed by type first, then hash order' '
+	test_must_fail git rev-parse 0000 2>stderr &&
+	grep ^hint: stderr >hints &&
+	grep 0000 hints >objects &&
+	cat >expected <<-\EOF &&
+	tag
+	commit
+	tree
+	blob
+	EOF
+	awk "{print \$3}" <objects >objects.types &&
+	uniq <objects.types >objects.types.uniq &&
+	test_cmp expected objects.types.uniq &&
+	for type in tag commit tree blob
+	do
+		grep $type objects >$type.objects &&
+		sort $type.objects >$type.objects.sorted &&
+		test_cmp $type.objects.sorted $type.objects
+	done
+'
+
+test_expect_success 'cat-file --batch and --batch-check show ambiguous' '
+	echo "0000 ambiguous" >expect &&
+	echo 0000 | git cat-file --batch-check >actual 2>err &&
+	test_cmp expect actual &&
+	test_i18ngrep hint: err &&
+	echo 0000 | git cat-file --batch >actual 2>err &&
+	test_cmp expect actual &&
+	test_i18ngrep hint: err
+'
+
+test_done